3 ms·
The memory is organized differently, where VGA has to use 4 memory chips and spread a byte of memory among them, while MCGA just keeps it simple and uses one by
by Dwedit 5mo ago
The memory is organized differently, where VGA has to use 4 memory chips and spread a byte of memory among them, while MCGA just keeps it simple and uses one byte of memory per pixel.
- rasz 5mo agoTechnically in MCGA mode VGA doesnt spread individual pixel bits among banks, pixels are kept "whole" as bytes in banks/planes. 13h is the only mode that doesnt benefit from all of that complicated EGA inherited machinery, yet it still became the most successful and practically synonymous with VGA :) Btw OG 1987 $595 IBM PERSONAL SYSTEM/2 DISPLAY ADAPTER https://www.minuszerodegrees.net/video/IBM%20Announcement%20Letter%20187-054.txt https://www.minuszerodegrees.net/video/IBM%20Announcement%20... VGA card used eight 64Kx4 DRAMs https://upload.wikimedia.org/wikipedia/commons/3/3f/IBM_VGA_graphics_card.jpg https://upload.wikimedia.org/wikipedia/commons/3/3f/IBM_VGA_... to build its 4 banks. Ram Address Bus is wired in parallel (can see pin10 A7 common for 2 rows of ram chips, also pin1 OE).